Deep well pumping apparatus



Oct. 10, 1967 E. A. BENDER 3,345,950

DEEP WELL PUMPING APPARATUS Filed April 29, 1966 ATTORNEYS United States Patent 3,345,950 DEEP WELL PUMPING APPARATUS Emil A. Bender, P.0. Box 52, Bakersfield, Calif. 93302 Filed Apr. 29, 1966, Ser. No. 546,356 8 Claims. (Cl. 103-206) The present invention relates to improved apparatus for deep well pumping, and is more particularly applicable to use in deep oil wells, since most of the very deep pumped wells produce oil.

During what is generally called the early life of an oil well, the reservoir pressure may be suflicient to enable it to produce oil without pumping, and this is done where it is permitted by the applicable regulatory authority. In any event, it will be desired eventually to pump the Well. Thishas generally been done in the art by utilizing a reciprocating force pump with the pump cylinder located in the producing horizon. The pump is ordinarily actuated by a walking beam power unit on the urface in which an end of the beam power unit is connected to the pump by a string of rods of standard dimensions.

As production of oil has progressed to more remote areas, this method has become progressively less efiicient. Many wells today are known to produce at levels of 5,000 to 8,000 feet and even deeper. It is evident that the stretching of the rods on the up-stroke, in itself, will amount to several feet which must be deducted from the nominal length of stroke of the pump besides allowing for other losses.

According to the invention there is erected adjacent the well, a tower somewhat greater in height than the length of the stroke of the pump to be used, and there is placed upon the tower a motor with suitable reduction gear, as required. Hung from each of the drive wheels on the motor assembly is one of a pair of flexible drive elements such as a chain, and suspended on the chain on one side thereof is the pumping string, while upon the opposite side of the drive wheels is a counterweight approximating the weight of the string of rods, plus onehalf of the fluid load so that there will be equal power used both ways. The motor is alternately actuated to raise and lower the string of rods. A braking system is built into the motor assembly to permit work on the well, as is frequently required, This brake may be spring loaded and so designed that it will stop and hold the load should any I malfunction of controls or breakage occur.

The above and other objects and advantages of the invention will become apparent upon full consideration of the following detailed description and accompanying drawings in which:

FIGURE 1 is a side elevation view, to a greatly reduced scale, with the central portion shown broken away, of the above ground structure of the present invention;

FIGURE 2 is a front elevation view taken at right angles to the view of FIG. 1 and facing the working side of the well;

FIGURE 3 shows a detail view of an alternate construction corresponding to the upper portion of FIG. 2; and

FIGURE 4 shows a detail view of another part of an alternate construction corresponding to the lower left portion of FIG. 1, and capable of cooperating with the embodiment of FIG. 3.

Referring now to the drawings, there is shown each of the four :corner posts of the tower. According to the loading of the tower, these may be made up of the proper size and shape of steel sections such as angles, channels and tubing. These rest upon a skid platform made up of additional sections 12 such as beams and the like. The platform facilitates movement of the tower from the well for service or repairs. The tower is built up with girts 14 of a fluid reservoir held at a 3,345,950 Patented Oct. 10, 1967 and braces 16 and surmounted with a top platform 18 for supporting the motor assembly, all supporting means 1048 being fabricated of appropriate steel sections welded or riveted together as is common in oil field practice. For ease in erection, the tower may be hinged at the rear at 20 and bolted or wedge-locked at the front (not shown) during use.

The well-head structure is schematically shown as including a casing 22, the uppermost rod 24 terminating in a threaded end 26, and having a packed cap 28 on the casing through which the rod passes. In practice, the structure including the apparatus through which the oil is discharged (not shown) is much more complex, but its description is not pertinent to this invention.

Mounted on the top platform 18 is motor assembly 30, and some of its details will be set out more specifically below. It has an output shaft 32 having on its outer ends toothed wheels 34, 34. These wheels and the chains 36 passing over them are preferred for their positive engagement, although it will be apparent that many equivalent devices may be substituted with varying degrees of efficiency.

The chains are secured at one end each thereof to the yoke 38 through which passes rod 24, held on the yoke by nut 40. It will be apparent that the section 12 of the skid platform supporting the pumping apparatus, upon being brought to the well-head, are carefully aligned with the well-head so that the pump rod 24 properly enters the bore of yoke 38. The opposite ends of the chains 36 are secured to the counterweight box 42. FIG. 2 shows the position of the box 42 and pump rod in solid lines at the beginning of the lifting stroke with other parts in cor-responding position. In addition, the position of the box 42 and arm 58 (mentioned below) at the end of the lifting stroke are shown in dash lines in FIG. 2.

It is found preferable to use a motor assembly 30 made up of. a hydraulic motor with a directly connected reduction gear and a remotely actuable brake. Such units are commercially available in numerous stock sizes. There are shown two chains 36, 36 and a yoke 38 for supporting the pump rod 24, since this is a conventional method in the oil well art and it balances the load on the motor assembly bearings. Appropriately, with a different design, a single support member may be used.

Hydraulic fluid under pressure for the operation of the hydraulic motor is provided by pump 44. Depending upon available facilities, it may be driven by electric, gas or diesel motor. Although in the drawing, for simplicity, the hydraulic pump 44 is shown directly connected to the fluid piping leading to the hydraulic motor assembly 30, it will be understood that better practice involves the use predetermined working pressure. The pump will then operate intermittently to keep up the working pressure.

The hydraulic pump 44 and motor assembly 30 forming a closed hydraulic circuit are shown connected to a four-way valve 46 by a double set of pipes 48 to the valve 46 from the motor assembly 30, and a pair of pipes 50, 52 to the valve 46 from the pump 44, the latter pipe being connected to a remote side of the valve not seen in FIG. 1. As in well known in the hydraulic art, the fourway valve 46 may be placed in two alternate positions permitting fluid to move in a steady direction in the pipes connecting the pump 44 and the valve 46, and permitting the direction of fluid flow between the valve and the motor assembly 30 to be reversed by a quarter turn of the valve 46 by shaft 54. In this manner, the direction of rotation of the Wheels 34, 34 may be determined.

A pump 44 preferred for use in this system is of the axial piston type, pumping in either direction via a supercharged closed system i.e., by shifting the pistons, the

flow will smoothly change directions. This system is well know in hydraulic applications, but it not known to have been used in pumping systems of any kind as related to the present invention. A pilot pump (not shown) usually is utilized to supercharge the closed circuit to make up for system leakage through the low pressure leg of the circuit. When the operating characteristics of a hydraulic system are extremely complex or the control requirements tight, a variable displacement circuit can offer many advantages from the standpoint of simplicity and small number of components required. Variable displacement circuits contain less valves, provide for easier piping and installation, and have fewer parts that require maintenance and adjustment.

An elongated actuating shaft 54 for the valve 46 extends across the pumping platform to a support bearing 56. Mounted on the shaft an an intermediate point is lower trip lever 58 actuated (as shown in FIG. 2) by the weight box 42, shown in dashed lines, as it reaches the lower point of its travel. Also mounted on the shaft 54 and adjacent bearing 56 is crank arm 60 connected by link 62 to upper trip arm 64 which is pivoted at element 66. Upper trip arm 64 is actuated by the pin 68 extending from yoke 38. The arrangement of the operating elements is such that, as the counterweight reaches its low point, the direction of the fluid in pipes 48 is set to cause the wheels 34, 34 (as shown in FIG. 1) to rotate clockwise to lower the rod 24 into the well. When the rod reaches it low position, the pin 68 strikes the upper trip lever 64 forcing it downwardly and reversing the direction of the apparatus.

By adding suflicient weight to box 42 to balance the string of rods in the well, the motor is only required to lift the weight of the oil on the pumping stroke. Still more weight may be added to equal the approximate weight of the oil lifted as well, or somewhat less than all of it. The load would thus be equally balanced by placing in the weight box half of the expected fiuid lift plus the weight of the rods. Since there is no drastic elongation produced in the rods due to the intermittent loading thereof, there is little variation in the length of the rods with consequent improvement in the pumping efficiency.

As an indication of the utility of the invention, an existing Well had a 1 /2 inch liner pump set at 8,000 feet using an air-balance unit with 7 foot strokes operating at 11 strokes per minute, producing 48 barrels per day. The approximate rod stretch was 4 feet, leaving only 3 feet of effective stroke. Upon installation of a 32-foot stroke pump operating less than 2 strokes per minute, a comparable counterbalance unit increased production 300%.

Although closure of valves in the hydraulic system tends to hold the hydraulic motor from rotation, there may be some leakage with corresponding slippage. Accordingly, it is preferable to employ a motor assembly incorporating a brake so that the counterweight may be held suspended while work is being performed on the well or pumping system.

Alternatively, an electrical drive system may be used as diagrammatically indicated in FIGS. 3 and 4. An induction m tor 70 w th bu lt in g rducer arrang m nt is shown in FIG.- 3 corresponding to and replacing essentially the upper portion of FIG. 2. FIG. 4 corresponds to the lower portion of FIG. 1 and shows a single-poledouble-throw type switch 72 replacing valve 46. A conductor cable 74 leads to enclosed switch board 76 containing suitable relays, power supply terminals and other apparatus for connecting a power supply to the motor to cause it to operate reversibly.

Additional embodiments of the invention in this specification will occur to others and therefore it is intended that the scope of the invention be limited only by the appended claims and not by the embodiments described hereinabove. Accordingly, reference should be made to the following claims in determining the full scope of the invention.

What is claimed is:

1. Pumping apparatus for an oil well of the like having a pump comprising a vertically reciporcating rod string actuated by reciprocating motive means, said pump mounted upon a tower having generally a greater height than the stroke of the reciprocating rod string of the pump and located above the oil well; a yoke receiving in coupling engagement the upper end of the pump rod string; a motor included in said motive means mounted at the top of the tower; a shaft also at the top of the tower driven by said motor; a wheel mounted outwardly on each end of said shaft; a flexible drive element trained over each of said wheels in positive driving relationship thereto and having one set of the companion ends of said elements being fixed to the yoke; a counterweight hung on the other set of companion ends of the drive element, and means for driving and braking said motor.

2. The invention of claim 1 wherein said reciprocating motive means is actuated by a mechanism to reverse the direction of the motive means when the rod string is in an upper and lower position of said stroke.

3. The invention of claim 2 wherein said mechanism is a lever means actuated by the position of said counterweight when at one end position of said stroke, and said lever means actuated by the yoke at the other end position of said stroke.

4. The invention of claim 3 wherein said reciprocating motive means is electrical.

5. The invention of claim 3 wherein said reciprocating motive means is hydraulic.

6. The invention of claim 5 wherein said reciproacting means is a supercharged closed circuit type system.

7. The invention of claim 4 wherein a single-poledouble-throw type switch is actuated by said lever means.

8. The invention of claim 5 wherein a four-way valve means in said hydraulic system is actuated by said lever means.

References Cited UNITED STATES PATENTS 3,153,387 10/1964 Sadovet l03-206 3,248,958 5/1966 Bender 74-590 ROBERT WALKER, Primary Examiner, 

1. PUMPING APPARATUS FOR AN OIL WELL OF THE LIKE HAVING A PUMP COMPRISING A VERTICALLY RECIPORCATING ROD STRING ACTUATED BY RECIPROCATING MOTIVE MEANS, SAID PUMP MOUNTED UPON A TOWER HAVING GENERALLY A GREATER HEIGHT THAN THE STROKE OF THE RECIPROCATING ROD STRING OF THE PUMP AND LOCATED ABOVE THE OIL WELL; A YOKE RECEIVING IN COUPLING ENGAGEMENT THE UPPER END OF THE PUMP ROD STRING; A MOTOR INCLUDED IN SAID MOTIVE MEANS MOUNTED AT THE TOP OF THE TOWER; A SHAFT ALSO AT THE TOP OF THE TOWER DRIVEN BY SAID MOTRO; A WHEEL MOUNTED OUTWARDLY ON EACH END OF SAID SHAFT; A FLEXIBLE DRIVE ELEMENT TRAINED OVER EACH OF SAID WHEELS IN POSITIVE DRIVING RELATIONSHIP THERETO AND HAVING ONE SET OF THE COMPANION ENDS OF SAID ELEMENTS BE ING FIXED TO THE YOKE; A COUNTERWEIGHT HUNG IN THE OTHER SET OF COMPANION ENDS OF THE DRIVE ELEMENT, AND MEANS FOR DRIVING AND BRAKING SAID MOTOR. 